Uterine artery embolization is directed to the removal of fibroids from the uterus. Fibroids are benign growths in the muscular wall of the uterus that can range in size from very small to quite large. Their known effects range from discomfort and backaches to interference with fertility.
There are many treatments available for women with fibroids. Medicine can shrink some fibroids, while surgery has been used in other cases. A relatively new way to treat women with fibroids is uterine fibroid embolization, which involves the cutting off of the fibroid's blood supply.
Fibroids require a supply of blood in order to grow, and will shrink or disappear completely when that supply is cut off. The embolization procedure entails the cutting of a tiny incision in the patient's groin region, and the passing of a small catheter through the patient's arterial system to the uterus. In practice, a radio-opaque catheter is fed into the femoral artery, while x-ray imaging is used to locate the relevant blood vessels and position the catheter. When the catheter has successfully navigated the arterial system to reach the targeted site, a fluid containing tiny particles is injected into the targeted area via the catheter. The particles, typically made of plastic or gelatin sponge, are about the size of grains of sand, and are moved by the pressure from the heart into the smaller arteries that are supplying blood to the fibroid. The particles become lodged in those arteries, and block blood flow to the fibroid. Over time, the fibroids consequently shrink or disappear.
In performing the embolization procedure, one must manipulate the catheter through a series of arteries and arterial branches of decreasing size in order to reach the targeted site. In accordance with well known techniques, the distal end of the catheter is inserted into the patient's femoral artery via the incision, and a thin, flexible, radio-opaque guide wire is advanced into and along the artery from the proximal end of the catheter. After advancing the wire for an appropriate distance, the catheter is advanced along the guide wire, the wire is further advanced, etc. Upon reaching a desired arterial branch, the wire is manipulated from the proximal end of the catheter so that its distal tip enters the desired branch and advances for some distance. The catheter is then advanced along the wire into and along the branch. This process is repeated until the desired site is reached.
Catheters must be sufficiently flexible to track the guide wire through sometimes tortuous paths, and must have an outer diameter that is sufficiently small to enter the arteries without causing damage. On the other hand, the catheters must be able to transmit the catheter-advancing longitudinally-directed force along the length of the catheter without kinking so that the catheter can be pushed through the patient's arterial system to reach the targeted area.